Block #322,031

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/20/2013, 4:56:28 PM · Difficulty 10.1986 · 6,483,658 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
e8626448593e1bf33c8f875d66f154487ab1573556bbaa436e1c1afc41fd8bf8

Height

#322,031

Difficulty

10.198634

Transactions

8

Size

2.56 KB

Version

2

Bits

0a32d9a8

Nonce

95,574

Timestamp

12/20/2013, 4:56:28 PM

Confirmations

6,483,658

Merkle Root

445317190761c900239006b83d59cbf617de890ecb5ead87ef1c944b4db0f342
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

3.659 × 10¹⁰⁷(108-digit number)
36590444813507484551…01754244368365547519
Discovered Prime Numbers
p_k = 2^k × origin − 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin − 1
3.659 × 10¹⁰⁷(108-digit number)
36590444813507484551…01754244368365547519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.318 × 10¹⁰⁷(108-digit number)
73180889627014969103…03508488736731095039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.463 × 10¹⁰⁸(109-digit number)
14636177925402993820…07016977473462190079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.927 × 10¹⁰⁸(109-digit number)
29272355850805987641…14033954946924380159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.854 × 10¹⁰⁸(109-digit number)
58544711701611975282…28067909893848760319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.170 × 10¹⁰⁹(110-digit number)
11708942340322395056…56135819787697520639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.341 × 10¹⁰⁹(110-digit number)
23417884680644790112…12271639575395041279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.683 × 10¹⁰⁹(110-digit number)
46835769361289580225…24543279150790082559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
9.367 × 10¹⁰⁹(110-digit number)
93671538722579160451…49086558301580165119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.873 × 10¹¹⁰(111-digit number)
18734307744515832090…98173116603160330239
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 consecutive prime numbers forming a Cunningham Chain of the First Kind. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

★★☆☆☆
Rarity
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,689,593 XPM·at block #6,805,688 · updates every 60s
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